same dang thing happened to me more or less. I was doing tests for the lag argument and I turned off target assist. well I forgot to turn it back on. the end result was that I thought I was being devoured by the rumored lag monster at last.
it took a few days for me to remember that it was off. once I realized that, i went "ooooooohhhhhhh" /on. ah thats better.
I honestly thought I was having bad lag issues. but even then I still had that really annoying voice in the back of my head going your missing... stop missing... its not lag... smack... its not lag... SMACK.
was a good read 